Bitcoin: the most important thing to know, in case of UASF BIP 148 & the chain might split

There will be a UASF (User Activated Soft Fork) on August 1st for BIP 148 (BIP=Bitcoin improvement Proposal, 148=SegWit) and there might be a chance that the chain might split. So what is the most important thing to ensure you are safe for August 1st?

I am not going to talk about all the technical details, there are others that can do that way better then me :) I am just giving you a heads up on the most important thing you need to know.